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The "Crunch" Flies

J

JohnF

Well Known Member
I flew the repaired RV-12 this morning. After a short flight the Dynon D-180 went nuts and said no oil pressure, so I made an immediate landing.
Subsequent investigation showed oil temp 15-degrees, CHT 10 and 12-degrees, MAP 52.9-inches, fuel pressure 86.1 psi, etc. Next time the unit was powered up things looked fairly normal. Next power down/up things kept changing. Called Dynon and got no tech support...had to leave a message.

Anyhow, plane flew well, no heavy wing, trimed out fine, climbed fine, landing had a lot more float than I like, and handling was fine.

I think there is some 'massive' intermittent in the D-180. Plugs were all pulled and re-seated, etc, with no change.

JohnF
 
Nice to hear John

After your first go round, this is good news. Hope you get the other issues under control soon also.

John Bender
 
John,

Congrats on getting your bird repaired and into the air!!

Do you think the crash of the first flight busted something inside the D180?

Most of the time it is a ground issue that causes everything to go wacko but since yours took a dive on the first flight maybe something got broken inside.

Does anything rattle around inside when you take the D180 out and twist it around?
 
Congratulations!

I'm mighty glad to hear this - um, except for the electronics. Sure hope that gets straightened out soon. Too bad it's coming up on a weekend for that.
 
D-180

No, the D-180 worked normally while I was doing a LOT of prop adjustments, and running it up looking for the static rpm I wanted, and also during some taxi tests...all very normal. This morning as I warmed up the engine and taxied out to the end of the runway (3/4 mile) everything was normal. Did runup mag checks, all OK. During takeoff still OK. In the air still OK. Suddenly the voice warning said "no oil pressure" - cause fo IMMEDIATE landing. and then the odd readings. Still waiting for some response from Dynon.
 
John, congrats on getting back in the air so quickly. Sorry about the Dynon issues. Welcome to the club.
Dick Seiders 120093
 
D-180

I talked to Dynon and they just had another D-180 come in with about the same indications; it checked OK on the bench. The Dynon tech is guessing that the problem is "loss of reference voltage" on Van's control board, but he can't be certain, and said I'd have to "go to Van's" for further help if the unit checks out OK, which he predicted it would. I sent the unit to Dynon to eliminate any 'box' problem anyway.

I sure wish I had a schematic diagram of the control board so I could trouble shoot it myself.
Anyway, the crucial question of whether or not the plane will fly properly has been resolved.
 
Congratulations

Congratulations John for a successful flight.
The 5 volt reference voltage comes from the Dynon D-180 EMS connector pin 18. A White/Red wire connects EMS pin 18 to the control board pin 1. From the control board, the 5 volt reference voltage goes to cylinder head temps, pitch trim, and manifold pressure. However, oil pressure and fuel pressure are powered independently from D-180 EMS pins 7 & 8 respectively. Next time there is a problem, take a look at the pitch trim indicator to see if it changes.
Sometimes a bad ground connection causes strange things to happen. Check the battery negative connections to the airframe and to the starter. Have the battery holder and oil tank holder been painted? Also check the ground wire from the panel base to the control board cover.
Monitor the 5VDC out on pin 18 of the Dynon EMS with a portable voltmeter with the negative lead connected to the Dynon case. If the 5VDC varies when everything goes haywire, then the fault is either internal to the Dynon or the EMS connector on the back of it.
Joe
 
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Good news John. You are certainly going to be in the running for " The RV-12 Perseverance Award" ! :D

Another -12 fledges from the nest.
 
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